Mechanical, Morphological and Thermal Characterization of Compatibilized Poly(lactic acid)/Thermoplastic Starch Blends

A two-step compounding procedure was used to produce binary blends composed of poly(lactic acid) (PLA)  and thermoplastic starch (TPS) with varying component ratios. Subsequently, three different chemical connectors were introduced in order to enhance the interfacial adhesion between the PLA and the TPS. Maleic anhydride, blocked isocyanate, and chain extender were used as coupling agents. Mechanical, morphological and thermal properties of PLA/TPS blends were determined. It was revealed that the initial interfacial adhesion between the components is weak. Out of the three coupling agents introduced, the chain extender proved to be the most effective, however, the improvement achieved in the mechanical properties was still marginal. According to the thermogravimetric analysis thermal stability was not significantly affected by any of the coupling agents.